Stationary induction apparatus having means



March 17, 1964 M. M. ARONSON ETAL 3,125,736

STATIONARY INDUCTION APPARATUS HAVING MEANS FOR REDUCING AUDIBLE souuu Filed Aug. 11. 1961 5 Sheets-Sheet 1 INVENTORS.

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4rraewi f March 17, 1964 M. M. ARONSON ETAL 3,125,736

STATIONARY INDUCTION APPARATUS HAVING MEANS I FOR REDUCING AUDIBLE SOUND 1 Filed Aug. 11, 1961 s Sheets-Sheet 2 INV EN TORS. l/aerm' M lemma ../0//,v A 65/41:

March 17, 1964 M. M. ARONSON ETAL 3,125,736

STATIONARY INDUCTION APPARATUS HAVING MEANS FOR REDUCING AUDIBLE SOUND Filed Aug. 11. 1961 3 Sheets-Sheet 3 United States Patent 3,125,736 STATIGNARY INDUCTION APPARATUS HAVlNG MEANS FUR REDUCING AUDIBLE SOUND Morton M. Aronson, Upper St. Clair Township, Bridgeville, and .lolrn F. Koepke, Bethel Park, Pa., assignors to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Aug. 11, 1961, ger- No. 130,920 14 Claims. (Cl. 336-100) This invention relates to stationary induction apparatus and, particularly, to enclosed stationary induction apparatus having means for reducing audible sound.

When a strip of iron is magnetized by alternating current flux, it changes dimension ever so slightly at the frequency of the alternating current. This change in dimension, called magnetostriction, occurs 120 times per second and is a vibration which creates an audible noise. Alternating flux in the steel laminations of the magnetic core of an electrical transformer causes them to change length due to magnetostriction and generate noise which is loud enough to be annoying under many circumstances. The magnetic core of atransformer is thus an oscillator or source of sound. Transformer core and coil assemblies are usually contained within metallic enclosures and are rigidly connected thereto by means of metallic connecting members. The members connecting the core and coil to the enclosure serve as conductors of the audible sound generated by the core. Sound is thus propagated from the sound source to the exterior of the transformer casing through the metallic members which connect the transformer core to the enclosing tank. This direct metallic coupling between core and tank exists at the bottom of the tank to which a supporting base may be firmly attached. The rigid base structure possesses the ability, when excited by the core, to drive the sidewalls of the tank to a high noise level. When resonance occurs in the base structure, the noise may be amplified to even higher levels.

It is an object of the invention to provide enclosed stationary induction apparatus having means for destroying the direct metallic coupling between the magnetic core and the enclosing tank.

Another object of the invention is to eliminate A.C. hum produced by an electrical transformer or at least reduce it to such degree as to be unobjectionaole.

It is a further object of the invention to provide an electrical transformer wherein the core and coil assembly is mechanically de-coupled from the enclosure and having means accessible from the exterior of the enclosure for restricting movement of the core and coil assembly relative to the enclosure during shipment.

The features of the invention which we believe to be novel are set forth with particularity in the appended claims. The invention both as to organization and to use, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a front view of an electrical transformer embodying the invention, partly in section, with the front tank wall removed and the core and coil assembly shown in operating position;

FIG. 2 is an end view of the transformer of FIG. 1 with the end tank wall removed and showing the core and coil assembly in shipping position;

FIG. 3 is a view taken along lines 3-3 of FIG. 1; and

FIG. 4 is a partial top view of the transformer of FIG. 1 with the tank cover and coils removed; and

FIG. 5 is a view taken along lines 5-5 of FIG. 3 with the core and coil assembly in shipping position, but showing alternate means for sealing between the tie-down bolts and the tank.

Referring now to the drawing, a metallic tank 10 housing a transformer core and coil assembly 11 and sealed at its open upper end by a cover 12 is supported upon a base 13 comprising horizontally spaced apart structural iron members 14. Core and coil assembly 11 includes a rectangular magnetic core 15 made up of a-plurality of magnetic steel laminations 16 forming a pair of vertical winding legs 18 connected by horizontal upper and lower yokes 19. Cylindrical transformer windings 20 surround the magnetic core legs 13.

Channel, structural iron, upper side frame members 22 are disposed on opposite sides of the upper core yoke 19 and afiixed thereto by bolts 23. Channel, structural iron, lower side frame members 24 are disposed on opposite sides of and aflixed to the lower core yoke 19 by bolts 26. The cylindrical windings 20 rest upon semi-annular plate members 27 which are secured to vertically disposed support members 28 welded to the lower side frame members 24. Semi-annular metal plates 30 are disposed above the coils 2t), and adjustable means for clamping the coils 20 to desired pressure in an axial direction includes nuts 32 welded to the lower leg of the channel upper side frame members 22 and socket bolts 33 threaded within the nuts 32 and bearing at their lower end against the semi-annular plates 30.

The height of the core and coil assembly 11 is minimized by the provision of cutout portions 35 at the ends along the bottom edge of the lower side frame members 24. Horizontal guide plates 36 extend transversely of the lower side frame members 24 within the cutout portions 35. Guide plates 36 are aifixed by bolts 38 to horizontal plates 39 upon which the cutout portions 35 of the lower side frame members 24 rest. Reinforcing gussets 40 are welded to the plates 39 and to the lower side frame members 24.

Two pair of tubular spring housings 42 with vertical axes are affixed to the bottom interior wall 43 of the tank 14) in spaced apart relation longitudinally of the lower side frame members 24, and the tubular housings 42 of each pair are spaced apart in a direction transverse of the lower side frame members 24. Resilient sleeves 45 line the tubular housings 42, and helical compression springs 46 coaxially disposed within the linings 45 and housings 42 normally extend above the open upper end of the housings 42. The resilient sleeve linings 45 prevent metal-tometal contact between the springs 46 and the housings 42. Each housing 42 includes a tubular metallic member 47 welded at its lower end to a circular base plate 43 which supports the lower end of the compression spring 46. The housings 42 are elevated above the tank bottom wall 43 by spring housing mounting plates 50 extending transversely of and welded to the tank bottom wall 43 and to the housing base members 48 for a purpose to be described hereinafter.

In the operating position of the transformer, the guide plates .36 rest upon the protruding upper end of the compression springs -46 to resiliently mount the core and coil assembly 11 and prevent metal-to-metal contact between the core and coil assembly 11 and the enclosure 10, thus destroying the direct metallic coupling which exists in conventional transformers for vibrations to be transmitted from the magnetic core to the enclosure. Such spring mounting of the core and coil assembly 11 interferes with the propagation of sound waves through the structural connecting members which conventionally rigidly connect the source of sound to the metallic enclosure. Such spring suspension of the core and coil assembly 11 prevents resonance in the base 13 and greatly reduces the audible sound transmitted to the exterior of the transformer casing. We have found that suspension of the core and coil assembly 11 by springs 46- having a static deflection of inch or greater reduces the natural fre- 3' quency of the suspension to 12 cycles per second or below and reactively decouples vibrations from the enclosure by greater than 99 percent.

Vertical guide bars 51 are secured in horizontally spaced apart relation to the interior surface of the end Walls 52 of the tank 10. Vertically disposed guide angles 54 are secured by bolts 55 to the ends of upper and lower side frame members 22 and 24' in spaced apart relation in a direction transverse of the side frame members. The guide angles 54 mate with the guide bars so that guide angle leg portions are inward of a guide bar in directions longitudinally and transverse of tank 16*, thus limiting movement of the core and coil assembly 111 relative to tank 10. During the tanking operation, the guide angles 54 slide relative to the guide bars 51 and cooperate therewith to locate the core and coil assembly 1 1 within the tank and guide it into its final approximate position as it is lowered into the enclosure.

Each guide plate 36 has a locating aperture 56 therein intermediate the tubular housings 42. Tapered, vertically disposed, lower guide pins 57 are secured to the housing mounting plates 50 between the tubular housings 42 of each pair. The lower guide pins 57 are slightly smaller in diameter than the apertures 56 in the guide plates 36 and are formed intermediate their ends with reduced diameter portions 59 having relatively large clearance with apertures 56. In the operating position of the transformer, the locating apertures 56 in the guide plates 36 encircle the reduced diameter portions 59 of the lower guide pins 57 to prevent metal-to-metal contact between the core and coil assembly 11 and the guide pins 57. As the core and coil assembly 1 1 is being lowered into its final approximate position in the tank, the tapered guide pins 57 project into the locating apertures 56 in the guide plates 36 to center the core and coil assembly 11 in its required position relative to the tank 10 and to locate the guide plates 36 properly on the compression springs 46.

The invention also comprehends means accessible from the exterior of the enclosure 16 for rigidly supporting the core and coil assembly 11 and restricting its movement relative to the enclosure 10' during shipment. Threaded tie-down rods 61 engaging the guide plates 36 extend through an enclosure wall to aposition where they are accessible to permit moving the core and coil assembly 11 down relative to tank 10 against the force of the compression springs 46 until the guide plates 36- are in metalto-metal contact with the upper end of the tubular housings 42. Relatively large apertures 62 and 63 are provided in the bottom tank wall 43 and mounting plate 56 respectively and smaller apertures 64 are provided in the spring housing base as axial of the tubular housings 4-2. The upper end of the tie down rods 61 extends through clearance apertures in the guide plates 36 and in the plates 39 and are threaded to nuts 65 positioned be tween each pair of gusset plates 40. The tie-down rods 61 extend freely through the apertures 62 and 64- in the bottom tank wall 43 and in the housing base 48, andmeans are provided to hermetically seal between the tiedown rods 61 and the tank 10'. As illustrated in FIG. 1, a gasket retainer member 66 having a sleeve portion 67 closely encircling tie-down rod 61 extends through the aperture 64 in the housing base 48, and the base retainer member 66 is secured to the housing base 48 by screws 69. A gasket 76 compressed within a circumferential groove in gasket retainer member 66 surrounding the sleeve portion 67 and compressed between the gasket retainer member 66 and the spring housing base 48 hermetically seals between these two members. Resilient O-ring gaskets 72 within circumferential grooves in the tie-down rods 61 are compressed between the tie-down rods 61 and the sleeve portion 67 to provide a seal for V the openings through the tank bottom wall 43.

In preparing the transformer for shipment, nuts 71 are threaded onto the accessible threaded lower end of the tie-down rod 61 and tightened against the gasket retainer members 66, thereby compressing the springs 46 and forcing the core and coil assembly 11 down relative to tank 16 against the force of the springs 46 until the guide plates 36 are in metal-to-metal contact with the upper end of the spring housings 42. In this shipping position, movement of the bottom of the core and coil assembly 11 relative to tank 16 is restricted because of the small clearance between the larger diameter portions of the lower guide pins 57 and the locating apertures 56 in the guide plates 36.

Upper guide means are provided for blocking the upper end of the core and coil assembly 11 against movement relative to the tank 10 during shipment of the transformer. Horizontally extending top guide plates 73 secured to the upper side frame members 22 have locating apertures 74- therein. Upper blocking angle members 76 secured by screws 77 to members welded to the end walls of the tank 10 support upper guide pins 78 which protrude into the locating apertures 74 in the top guide plates 73. The upper guide pins 78 are slightly smaller in diameter than the locating apertures 74 and have reduced diameter portions 81) at their 'upper end which are encircled by the locating apertures 74 when the trans former is resiliently supported by springs 36 in operating position. In operating position the relatively large clearance between locating apertures 74 and reduced diameter portions 80 prevents metal-to-metal contact between the core and coil assembly 11 and the enclosure '10 and thus interferes with the propagation of the sound waves from the source of sound to the enclosure, whereas in the shipping position of the transformer the locating apertures 74 have a relatively close fit with the larger diameter portion of the guide pins 7 8 and restrict movement of the upper portion of the core and coil assembly 11 relative to the tank 10.

Because of the relative inaccessibility of the gasketed joints of the tie-down rods 61, additional sealing is provided for the openings in the bottom tank wall 43. Tiedown nut housings 81 affording such additional sealing comprise steel rings 82 welded at their upper ends to the exterior of the bottom tank wall 43 in encircling relation to the threaded accessible end of the tie-down rods 61 and annular members 83 welded to the lower end of the steel rings 82. A circular cover 84 for tie-down nut housing 81 is secured by screws 65 to the annular member 83 and sealed to the housing 81 by a continuous resilient gasket 86 compressed within a circumferential groove surrounding the opening in annular member 83. The tie-down nut housings 81 additionally protect the protruding portion of the tie-down rods 61 from accidental damage that may occur during installation of the transformer.

FIG. 5 illustrates alternative means for sealing between tie-down rod 61 and the gasket retainer member and also illustrates the transformer in the shipping position wherein the guide plates 36 are in metal-to-rnetal contact with' the upper end of the tubular housings 42. In this emportion 90 with an axial aperture therethrough for re ceiving tie-down rod 61, suitable packing 91 is positioned Within the cup-shape portion 90 in surrounding relation to tie-down rod 61, and a packing gland member 92 having a tubular portion surrounding tie-down rod 61 and extending into cup-shape portion 90 compresses the packing 91 to etfect a seal between tie-down rod 61 and the gasket retainer 89. Packing gland member 92 is secured by screws 93 to the gasket retainer 89. r

The mounting plates 50 elevate the spring housings 42 above the tank bottom wall 43 to prevent extension of the tie-down rods 61 below the transformer base 13.

In the shipping position of the transformer the tiedown nuts 71 are tightened on the tie-down rods 61 until prepare the transformer for service, metal-to-metal contact between the core and coil assembly 11 and the tank is relieved by removing the covers 84 on the tie-down nut housings 81 and loosening the tie-down nuts 71 and removing them completely from the tie-down rods 61. This allows the compression springs 46 to raise the core and coil assembly 11 until the guide plates 36 are spaced from the upper end of the tubular housings 42 and places the lower and upper locating apertures 56 and 74 in the lower and upper guide plates 36 and 73 opposite the reduced diameter portions $9 and 8@ on the upper and lower guide pins 57 and 78 respectively. The large clearance between the locating holes and the reduced diameter portion of the guide pins assures that metal-to-metal contact cannot occur betweenithe core and coil assembly 11 and the enclosure ill? and that the direct metallic coupling between the source of sound and the enclosure is destroyed.

While only a single embodiment of our invention has been shown and described, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall Within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a tank, a transformer core within said tank having winding legs connected by upper. and lower yokes, electrical coils surrounding said winding legs, upper and lower side frame members disposed on opposite sides of and aflixed tov said upper and lower yokes, said lower side frame members having cutout portions along the bottom surface, thereof, two pair of tubular housings with vertical axes affixed to the bottom interior wall of said tank withisaid pairs spaced apart longitudinally of said side frame members and the housings of each pair spaced apart transversely thereof, a horizontal member disposed above each said pair of housings beneath said lower side frame members and within said cutout portion and extending transversely of said lower side frame members, resilient sleeveslining said housings, helical springs disposed coaxially within said sleeves and said housings and extending above the upper end of said housings and resiliently supporting said side frame members and said core and coil in spaced relation to said housings, said tank bottom wall having openings therethrough axially of said housings, tie-down rods extending through said openings and being affiXCd/[O said horizontal members Within said tank and being threaded at the lower end thereof beneath said tank bottom wall, means including resilient gaskets surrounding said tie-down rods for sealing said openings, and a base affixed to said tank for raising said bottom tank wall above the. surface. upon which said tank is supported, whereby said threaded end of said tie-down rods is accessible from the exterior of said tank for engagement with a nut to permit pulling said side frame members down relative to said tank against the upper end of said housings during shipment.

2. In combination, a tank, tubular housings for springs affixed in spaced apart relation with vertical axes to the bottom interior wall of said tank, helical springs coaxially disposed within and extending above the upper end of said housings, a magnetic core, electrical coils linked with said core, side frame members disposed on opposite sides of and affixed to said core, members resting upon said springs and extending transversely of and below said frame members and being afiixed thereto, said bottom tank wall having openings therethrough axial of said housings, threaded members engaging said transverse members and extending freely through said openings and adapted to be engaged by nuts exterior of said tank for pulling said core and coil down relative to said tank against the force of said springs until said transverse members engage the upper end of said housings, resilient gaskets surrounding said threaded members, means afiixed to said tank and surrounding said threaded members and said gaskets for compressing said gaskets against said threaded members to seal said tank against leakage through said openings, a base having horizontally spaced apart portions beneath said tank for raising the tank above the surface on which it is supported, and guide means including at least one pair of interengaging members of slightly different diameter one of which is affixed to said tank and the other of which is affixed to said frame for restricting horizontal movement of said core and coil assembly relative to said tank when said frame is pulled down by said tie-down bolts into engagement with said housings, said guide means providing clearance between said interengaging members when said frame is resiliently supported on said springs.

3. An electrical transformer having means to reduce audible sound, comprising, in combination, a tank, a transformer core and coil assembly Within said tank having frame members disposed on opposite sides thereof, tubular housings with vertical axes secured in horizontally spaced apart relation to the bottom interior wall of said tank, springs within said housings supported from said bottom tank wall and extending above the upper end of said housings, horizontal guide members extending transversely of and ariixed to said frame members and resting on said springs, each of said guide members having an aperture therein, a plurality of vertical guide pins supported from said bottom wall each of which is slightly smaller in diameter than said aperture and has a reduced diameter portion which has a relatively large clearance with said aperture, each guide pin projecting into one of said apertures in a position wherein said aperture encircles said reduced diameter portion in the operating position of said transformer, and detachable means engaging said guide members and said tank for moving said guide members and said core and coil down relative to said tank against the force of said springs until said guide members abut against the upper end of said housings and said aperture is opposite the larger diameter portion of said guide pin, whereby said core and coil assembly may be rigidly supported from said tank bottom wall and movement of said core and coil assembly restricted during shipment of said transformer.

4. In combination, a hermetically sealed tank, a transformer core and coil assembly within said tank having a frame with portions disposed on opposite sides of and afiixed to said assembly, means for guiding said core and coil assembly within said tank and restricting movement of said assembly relative to said tank during shipment of said transformer including at least one pair of members one of which carries a pin having a reduced diameter portion and the other of which has an aperture having a slightly larger diameter than said pin but having relatively large clearance with said reduced diameter portion, spring means between the bottom wall of said tank and said frame for resiliently mounting said core and coil assembly in an operating position wherein it is mechanically de-coupled from said tank and said aperture encircles said reduced diameter portion of said pin, and means engaging said frame and having at least one member extending through an opening in the bottom wall of said tank and being accessible from the exterior of said tank for pulling said core and coil assembly down against the force of said spring means until said frame is rigidly supported from said bottom tank wall and said aperture encircles said larger diameter portion of said pin, said member being detachable from said tank bottom wall in said operating position, and resilient means for sealing between said member and the portion of said bottom tank wall defining said opening, whereby said core and coil assembly may be pulled down into rigid engagement with said tank for shipping without breaking the seal of the tank and exposing the interior of said tank to the atmosphere and may also be released at the operating site to said operating position wherein said core and coil assembly is resiliently mounted and mechanically decoupled from the tank without breaking said seal.

5. In combination, a hermetically sealed tank, a transformer core and coil assembly within said tank, a frame aifixed to said assembly, spring means between the bottom wall of said tank and said frame for resiliently mounting said core and coil assembly in an operating position wherein it is mechanically de-coupled from said tank, means engaging said frame and having a member extending through a wall of said tank and being accessible from the exterior of said tank for moving said core and coil assembly down relative to said tank against the force of said spring means until said frame is rigidly supported from the bottom wall of said tank, said member being detachable from said tank wall in said operating position,

resilient means for hermetically sealing between said member and said tank wall, and guide means including at least one pair of interchanging members of slightly different diameter one of which is affixed to said tank and the other of which is affixed to said frame for restricting movement of said core and coil assembly relative to said tank when said frame is moved down until said core and coil assembly is rigidly supported from said tank bottom wall, said guide means providing relatively large clearance between said interengaging members when said frame and core and coil assembly is resiliently supponted on said springs in said operating position, whereby said core and coil assembly may he pulled down until it is rigidly supported from said bottom wall for shipment and also released to said operating position at the operating site without breaking the seal of the tank and exposing the interior of the tank to the atmosphere.

6. In combination, a hermetically sealed tank, a tran former core and coil assembly within said tank, a frame afiixed to said assembly, spring means between the bottom wall of said tank and said frame for resiliently mounting said core and coil assembly in an operating position wherein it is mechanically de-coupled from said tank, means engaging said frame and said tank and being operable from the exterior of said tank without opening the seal of said tank for moving said core and coil assembly down relative to said tank against the force of said spring means until it is rigidly supported from said tank bottom wall and also being detachable from said tank during operation of said transformer without opening the seal of said tank, and guide means including at least one pair of interengaging members of slightly different diameter one of which is affixed to said tank and the other of which is aifixed to said frame for restricting movement of said core and coil assembly relative to said tank when said frame is pulled down until said core and coil assembly is rigidly supported from said tank bottom wall, said guide providing relatively large clearance between said interengaging members when said frame is resiliently supported on said spring means in said operating position.

7. In combination, a hermetically sealed tank, a transformer core and coil assembly within said tank, a frame affixed to said assembly, spring means between the bottom wall of said tank and said frame for resiliently mounting said core and coil assembly in an operating position wherein it is mechanically de-coupled from said tank, and means engaging said frame and having a member extending through a wall of said tank and being accessible from the exterior of said tank for moving said core and coil assembly down relative to said tank against the force of said spring means until said frame is rigidly supported from said tank bottom wall, said member being detachable from said tank Wall, whereby movement ofsaid core and coil assembly relative to said tank may be restricted during shipment of said transformer and said core and coil released to said operating position at the operating site without opening the seal of said tank and exposing the interior of said tank to the atmosphere,

and means for hermetically sealing between said mem:

her and said tank wall.

8. In combination, a hermetically sealed tank, tubular housings with vertical axes atiixed in spaced apart relation to the bottom tank wall interior of said tank, compression springs within said housings supported from said bottom tank wall and extending above the open end or" said housings, a transformer core and coil assembly having a frame afiixed thereto resting upon said springs, whereby said core and coil assembly in its operating position is resiliently mounted on said springs and mechanically de-coupled from said tank, said bottom tank wall having openings therethrough axial of said housings, detachable means including tie-down bolts engaging said frame and extending through said openings and being accessible from the exterior of said tank for pulling said core and coil assembly down relative to said tank against the force of said springs until said frame is in direct engagement with the upper end of said housings, and means including resilient gaskets surrounding and compressed against said tie-down bolts for sealing between said tie-down bolts and said tank, whereby said core and coil assembly may be pulled down until said frame is. in direct engagement with said housings and then released at the operating site to said operating position wherein it is resiliently mounted on said springs without breaking the seal of the tank and exposing the interior of the tank to the atmosphere.

9. In combination, a hermetically sealed tank, a transformer core and coil assembly within said tank, a frame afiixed to and having portions on opposite sides of said core and coil assembly, spring means between the bottom -wall of said tank and said frame for resiliently supporting said core and coil assembly and mechanically de-coupling it from said tank, vertically spaced apart upper and lower guide means for restricting movement of said core and coil assembly relative to said tank during shipment,

each guide means including at least one member affixed to said frame and at least one member affixed to said tank, one of said members carrying a pin having a reduced diameter portion and the other of said members having an aperture therein of slightly larger diameter than said pin but having relatively large clearance with said reduced diameter portion, said spring means normally supporting said core and coil assembly in an operating position wherein said aperture encircles said reduced diameter portion of said pin, and detachable interengaging means between said frame and said tank for moving said core and coil down relative to said tank against the force of said springs to a position wherein said frame is 'rigidly supported from said tank bottom wall and said aperture surrounds the larger diameter portion of said pin,

'within one of said cutout portions, two horizontally spaced'apart pair of tubular housings with vertical axes afiixed to the bottom interior wall of said tank with the housings of each said pair spaced apart in a direction transverse of said frame members, resilient sleeves lining said housings, helical springs disposed coaxially within' said housings and said sleeves supported on said bottom tank wall and normally extending above the open end of said housings, each said guide member resting upon the springs within one of said pairs of housings and having an aperture therein between said housings, a pair of vertical guide pins slightly smaller in diameter than said aperture supported on said bottom tank Wall, each of said pins extending into one of said apertures and being formed with a reduced diameter portion having a relatively large clearance with said aperture and being encircled by said aperture in the operating position of the transformer when said core and coil assembly is resiliently supported on said springs, said bottom tank wall having openings therethrough axially of said housings, and adjustable bolt means extending through said open-ings with a loose fit and engaging said transverse members for pulling said frame members down relative to said bottom tank wall against the force of said springs until said guide members engage said housings and said aperture is opposite the larger diameter portion of said guide pins, and means to hermetically seal between said bolt means and said tank, whereby said core and coil is resiliently mounted during operation in a position wherein it is mechanically de-coupled from said tank and may be pulled down into rigid engagement therewith for shipping.

11. In combination, a metallic tank, a transformer core within said tank having winding legs connected by upper and lower yokes, electrical coils surrounding said winding legs, upper and lower side frame members disposed on opposite sides of and afiixed to said upper and lower yokes, said lower side frame members having cutout portions along the bottom edge thereof, two pair of tubular housings with vertical axes affixed to the bottom interior wall of said tank with said pairs spaced apart longitudinally of said side frame members and the housings of each pair spaced apart transversely thereof, a horizontal guide member disposed above each said pair of housings and beneath said lower side frame members and within said cutout portion 'and extending transversely of said lower side frame members, resilient sleeves lining said housings, helical springs disposed coaxially within said sleeves and said housings and extending above the upper end of said housings and resiliently supporting said side frame members and said core and coil in spaced relation to said housings, said tank bottom wall having openings therethrough axially of said housing, tie-down rods extending through said openings and being afiixed to said horizontal guide members within said tank and being threaded at the lower end thereof beneath said tank bottom wall, means including gaskets surrounding said tie-down rods for sealing said openings, a base afiixed to said tank for raising said bottom tank wall above the surface upon which the tank is supported, whereby said threaded end of said tie-down bolts is accessible from the exterior of said tank for engagement with a nut to permit pulling said side frame members down against the upper end of said housings, during shipment, each said horizontal guide member having an aperture therein, and a pair of vertical guide pins each of which is slightly smaller in diameter than said aperture and has a reduced diameter portion having a relatively large clearance with said aperture and is affixed to the interior of the bottom tank wall between said tubular housings of one of said pairs and extends into said aperture to a position wherein said reduced diameter portion is encircled by said aperture when said core and coil is resiliently supported on said springs in the operating position of said transformer, said aperture encircling the larger diameter portion of said pin when said core and coil is pulled down by said tie-down rods until said horizontal guide members engage said housings in the shipping position of said transformer.

12. In combination, .a metallic tank, a transformer core within said tank having winding legs connected by upper and lower yokes, electrical coils surrounding said winding legs, upper and lower side frame members disposed on opposite sides of and affixed to said upper and lower yokes, said lower side frame members having cutout portions along the bottom edge thereof, twopair of tubular housings with vertical axes afiixed to the bottom interior wall of said tank with said pairs spaced apart longitudinally of said side frame members and the housings of each pair spaced apart transversely thereof, a horizontal guide membe) disposed above each said pair of housings and beneath iii said lower side frame members and within said cutout portion and extending transversely of said lower side frame members, resilient sleeves lining said housings, helical springs disposed coaxially within said sleeves and said housings and extending above the upper end of said housings and resiliently suporting said side frame members and said core and coil in spaced relation to said housings, said tank bottom wall having openings therethrough axially of said housing, tie-down rods extending through said openings and being affixed to said horizontal guide members within said tank and being threaded at the lower end thereof beneath said tank bottom wall, means including gasket means surrounding said tie-down rods for sealing said openings, a base aifixed to said tank for raising said bottom tank wall above the surface upon which the tank is supported, whereby said threaded end of said tie-down rods is accessible from the exterior of said tank for engagement with a nut to permit pulling said horizontal guide members down against the upper end of said housings during shipment, each said horizontal member having an aperture therein, and a pair of vertical guide pins each of which has a slightly smaller diameter than said aperture and has a reduced diameter portion having a relatively large clearance with said aperture and is affixed to the interior of the bottom tank wall between said housings of one of said pairs and extends into said aperture to a position wherein said reduced diameter portion is encircled by said aperture when the transformer core and coil is resiliently supported on said springs in the operating position of said transformer, said aperture encircling the larger diameter portion of said pin when said lower side frame members are pulled down by said tie-down rods until said horizontal guide members rest upon said housings in the shipping position of said transformer, guide means for restricting movement of the upper portion of said core and coil relative to said tank during shipment including at least one pair of members one of which is affixed to the sidewall of said tank and the other of which is aflixed to an upper side frame member, one of said members having an aperture therein and the other carrying a vertical upper guide pin having a slightly smaller diameter than said aperture and having a reduced diameter portion with a relatively large clearance relative to said aperture, said reduced diameter portion of said upper guide pin being encircled by said aperture when said lower side frame members are resiliently supported by said springs in the operating position of the transformer, said aperture encircling the larger diameter portion of said upper guide pin when said horizontal guide members are pulled down against the upper end of said tubular housings in the shipping position of the transformer.

13. In combination, a tank, tubular housings for springs afiixed in spaced apart relation with vertical axes to the bottom interior wall of said tank, resilient sleeves lining said housings, helical springs coaxially disposed within said housings and said sleeves and extending above the upper end of said housings, a magnetic core, electrical coils linked with said core, side frame members disposed on opposite sides of and affixed to said core, members resting upon said springs extending transversely of and below said frame members and being aflixed to said frame members, said bottom tank wall having openings therethrough axial of said housings, tie-down bolts engaging said transverse members and extending freely through said openings and adapted to be engaged by nuts exterior of said tank for pulling said core and coil down against the force of said springs until said transverse members engage the upper end of said housings, resilient gaskets surrounding said tie-down bolts, means affixed to said tank and surrounding said tie-down bolts and said gaskets for compressing said gaskets against said bolts to seal said tank against leakage through said openings, and a base having horizontally spaced apart portions beneath said tank for raising the tank above the surface on which it is supported.

14. In combination, a tank, tubular housings with ver- 1 1 tical axes afiixed in spaced apart relation to the bottom tank Wall interior of said tank, compression springs c0- axially disposed within said housings supported from the bottom tank wall and extending above the open end of said housings, a transformer core and coil assembly having frame members disposed on opposite sides of and affixed to said core and having cutout portions along the bottom edge thereof, support members extending transversely of and beneath said frame members within said cutout portion and resting upon said springs, whereby said core and coil assembly is resiliently mounted on said springs and mechanically decoupled from said tank, said bottom tank wall having openings therethrough axial of said housings, means including tie-down members engaging said support members and extending through said openings and being accessible from the exterior of said tank for pulling said core and coil assembly down relative to said tank against the force of said springs until said frame members are in engagement with the upper end of said housings, means including resilient gaskets surrounding said tie-down members for sealing between said tie-down members and said bottom tank Wall, and a base beneath said tank for raising said bottom tank wall above the surface upon which the transformer is supported.

References Cited in the file of this patent UNITED STATES PATENTS 2,277,505 Barker et a1. Mar. 24, 1942 2,714,184 Peck July 26, 1955 2,734,096 Ennis Feb. 7, 1956 2,822,527 Terry Feb. 4, 1958 

7. IN COMBINATION, A HERMETICALLY SEALED TANK, A TRANSFORMER CORE AND COIL ASSEMBLY WITHIN SAID TANK, A FRAME AFFIXED TO SAID ASSEMBLY, SPRING MEANS BETWEEN THE BOTTOM WALL OF SAID TANK AND SAID FRAME FOR RESILIENTLY MOUNTING SAID CORE AND COIL ASSEMBLY IN AN OPERATING POSITION WHEREIN IT IS MECHANICALLY DE-COUPLED FROM SAID TANK, AND MEANS ENGAGING SAID FRAME AND HAVING A MEMBER EXTENDING THROUGH A WALL OF SAID TANK AND BEING ACCESSIBLE FROM THE EXTERIOR OF SAID TANK FOR MOVING SAID CORE AND COIL ASSEMBLY DOWN RELATIVE TO SAID TANK AGAINST THE FORCE OF SAID SPRING MEANS UNTIL SAID FRAME IS RIGIDLY SUPPORTED FROM SAID TANK BOTTOM WALL, SAID MEMBER BEING DETACHABLE FROM SAID TANK WALL, WHEREBY MOVEMENT OF SAID CORE AND COIL ASSEMBLY RELATIVE TO SAID TANK MAY BE RESTRICTED DURING SHIPMENT OF SAID TRANSFORMER AND SAID CORE AND COIL RELEASED TO SAID OPERATING POSITION AT THE OPERATING SITE WITHOUT OPENING THE SEAL OF SAID TANK AND EXPOSING THE INTERIOR OF SAID TANK TO THE ATMOSPHERE, AND MEANS FOR HERMETICALLY SEALING BETWEEN SAID MEMBER AND SAID TANK WALL. 